1. Field of the Invention
The invention relates generally to wireless electronic communications and more particularly to antenna tuning systems and methods.
2. Background
In a communication system with different transmit and receive frequencies, mobile station antenna efficiency is a balance between optimization for the transmit frequency and optimization for the receive frequency. Under typical operating conditions, the typical antenna efficiency balance allows for the best use of the transmit and receive resources. However, commonly, conditions occur in which the typical antenna efficiency balance is not preferred. In such conditions, it can be said that the forward and reverse links are not balanced.
The forward link is the communication link for data (voice data or other data) travelling from a base station transmitter to a mobile station receiver. The reverse link is the communication link for data (voice data or other data) from the mobile station transmitter to the base station receiver.
When a mobile station is in an acquisition state, the mobile station does not transmit any signal. Acquisition state means that the mobile station is attempting to acquire a channel, that is, the mobile station is attempting to find a pilot channel or a synchronization (SYNC) channel of a base station. This is commonly referred to as scanning for a channel.
A mobile station in acquisition state typically uses a preferred roaming list (PRL) to control the scanning. The PRL is a prioritized list of channels that the mobile station scans when looking for a pilot channel of a base station. A PRL is stored in the memory of the wireless communication device. The PRL contains records of all of the wireless communication systems or networks that the wireless communication device can communicate with. Several examples of using PRL's are described in U.S. Pat. No. 5,995,829, issued Nov. 30, 1999; U.S. Pat. No. 6,415,148 B1, issued Jul. 2, 2002; U.S. Pat. No. 6,466,802 B1 issued Oct. 15, 2002; U.S. patent application No. 2003/0134637 A1 published Jul. 17, 2003; U.S. patent application No. 2004/0110503, published Jun. 10, 2004; and U.S. patent application No. 2004/0121781 A1, published Jun. 24, 2004, which are each hereby incorporated in whole herein by reference.